Capillary Deliquification Safety System

Transcription

1 Capillary Deliquification Safety System Dick Klompsma Nederlandse Aardolie Maatschappij Douglas Westera Venture Production Nederland Bert de Vries Halliburton

2 Introduction: Liquid loading of gas wells in mature fields is a common problem in the industry. A method to manage this problem is the use of surfactants as foaming agents to artificially unload the well. The preferred method allows automatic and continuous delivery of these surfactants. Safety legislation requires a Subsurface Safety Valve being operational during injection. Joint development between NAM and Halliburton to develop the Capillary Deliquification Safety System.

3 Principle: Typical downhole completion with Wireline Retrievable Safety valve installed in a Safety Valve Landing nipple. The downhole Safety Valve is operated by the control line.

4 Principle: Typical downhole completion with Wireline Retrievable Safety valve installed in a Safety Valve Landing nipple. The downhole Safety Valve is operated by the control line.

5 Principle: Typical downhole completion with Wireline Retrievable Safety valve installed in a Safety Valve Landing nipple. The downhole Safety Valve is operated by the control line. It s the use of the existing control line for Capillary Deliquification that makes this system unique in the industry.

6 How are the surfactants injected: Surfactants are injected into the well via a control line, Wireline-retrievable safety valve, foam injection back pressure valve, capillary tubing and a downhole foam injection valve. Capillary tubing's are generally 1/4 or 3/8 stainless steel run inside existing tubing or casing. Capillary tubing's are run into the well under pressure in a method similar to running coiled tubing into a live well bore. The Capillary String is providing the Surfactants to a specified point within the well bore / completion. The Halliburton Wireline-retrievable safety Valve with chemical Injection feature facilitates delivery of the surfactants whilst maintaining the purpose and functionality of a production downhole safety device.

7 How it works: Capillary Deliquification Safety System operates via the control line for the Safety Valve. When the control line pressure reaches a predetermined pressure, the Wirelineretrievable safety valve opens followed by the foam injection back pressure valve and the downhole foam injection valve. Use of existing control line provides a cost effective method of installing an injection system without the need to modify the wellhead. Safety Valve Back Pressure Valve Back Pressure Valve

8 How it works: Capillary Deliquification Safety System operates via the control line for the Safety Valve. When the control line pressure reaches a predetermined pressure, the Wirelineretrievable safety valve opens followed by the foam injection back pressure valve and the downhole foam injection valve. Use of existing control line provides a cost effective method of installing an injection system without the need to modify the wellhead.

9 How it works: Capillary Deliquification Safety System operates via the control line for the Safety Valve. When the control line pressure reaches a predetermined pressure, the Wirelineretrievable safety valve opens followed by the foam injection back pressure valve and the downhole foam injection valve. Use of existing control line provides a cost effective method of installing an injection system without the need to modify the wellhead.

10 How it works: Capillary Deliquification Safety System operates via the control line for the Safety Valve. When the control line pressure reaches a predetermined pressure, the Wirelineretrievable safety valve opens followed by the foam injection back pressure valve and the downhole foam injection valve. Use of existing control line provides a cost effective method of installing an injection system without the need to modify the wellhead.

11 How it works:

12 How it works:

13 How it works: The downhole foam injection valve is run into the well with coil tubing.

14 How it works: The Slip Rams close. Capillary tubing is cut and Coil Tubing is removed.

15 How it works: The Wireline-retrievable safety valve and the foam injection back pressure valve are connected to the capillary tubing and the assembly is run into the well with Slick line.

16 How it works: The Wireline-retrievable safety valve and the foam injection back pressure valve are connected to the capillary tubing and the assembly is run into the well with Slick line.

17 How it works: On reaching the Safety Valve Landing Nipple the keys will lock the assembly in place.

18 How it works: The assembly is set in the Safety Valve Landing Nipple nipple. The Wireline Retrievable Safety Valve can now be opened through the existing Surface Control Line. The Flapper will open. Control line pressure increase will open the foam injection back pressure valve and subsequently the downhole foam injection valve.

19 How it works: The Capillary Deliquification Safety System is operational and the well is protected.

20 Identifying the parts: Foam Inlet Conduit Conventional Wireline Retrievable Safety Valve Foam Injection back pressure Control Valve Housing Connector

21 Details:

22 Options: A Safety Valve Landing Nipple installed in a new well for eventual future Foam Injection. During installation, this valve has no communication with the control line. With a special communication tool, a hole can be punched to enable communication. This will give each well the option to use the capillary deliquification Safety System if required.

23 Features: The design is based upon proven Subsurface Safety Valve Technology. The Valve can be installed into existing completions with a suitable safety valve landing nipple profile or inside a Tubing Retrievable Safety Valve. Unique design allows system installation with no requirement for wellhead modification. Reducer nipple s allows the use for various well sizes: 2.75 up to

24 Lessons Learned: Feel for running capillary. Injection Valve maintenance. Metallurgy selection. Foam selection with reference to corrosion. Perforations damaging capillary.

25 Capillary String Experience Nederlandse Aardolie Maatschappij Number of installations: 13 Safety Valve size: ; ; ; Safety Valve depth 86 m till 595m Capillary string sizes 1/4" x & 1/4" x Capillary string depth 1237m till 4125m Foam injection rates liters per day Gas production gains Up to Nm³/day

26 Offshore Capillary String Experience Venture Production Nederland B.V. to Prevent Halite Precipitation Gas well, 7, 5½, 5 and 4½ tubing, 5 liner ~3770 m deep, max. deviation 32.7 WRSV at ~216 m, length capillary string ~3550 m Perforated interval length 37 m Potable water injection rates 3-4 m3/day Experience to date Good success on continuous water injection Well produces approximately 130,000 Nm3/day First offshore installation in the world of it s type Continuous water injection 2nd installation by Q Implement continuous foam injection in two installations by Q Objective simultaneously battle liquid loading & halite precipitation via use of capillary string technology Way Forward